1. Field of the Invention
The present invention relates to a door glass run for attachment along an inner periphery of a motor vehicle door frame.
2. Description of Related Art
As shown in FIG. 1, in a motor vehicle door 1, a door glass run (hereinafter referred to as "glass run") 3 is continuously attached along an inner periphery of a door frame 2 to guide a door glass 6 to its closed and open positions. When the door glass 6 is elevated to its fully closed position, the glass run 3 effects a seal between the door glass 6 and door frame 2.
The glass run 3 is generally composed of rubber, elastomer or synthetic resin, and is formed by continuously connecting extruded glass runs 3A, 3B and 3C via molded corner parts 3D and 3E. The glass run 3 has an approximately identical cross-section over the entire length thereof, and as shown in FIG. 2, includes a main body 30 having a generally U-shaped cross-section. The main body 30 includes a bottom wall 31 and side walls 32a and 32b which face each other. Seal lips 33a and 33b extend inwardly from ends of the side walls 32a and 32b, and molding lips 34a and 34b extend outwardly from the ends of the side walls 32a and 32b and turn upwardly.
To attach the thus arranged glass run 3 to the door frame 2, the main body 30 is mounted into a channel 20 having a U-shaped cross-section, which is formed along the inner periphery of the door frame 2, so as to hold walls of the channel 20 with molding lips 34a and 34b and side walls 32a and 32b of the main body 30. Seal lips 33a and 33b seal the periphery of the door glass 6 from both sides thereof.
There is another type of glass run, which has no molding lips, but instead, has projections at ends of the side walls of a main body thereof for covering the ends of the side walls of the channel 20 to be fitted thereon.
It is difficult to form the glass runs 3A, 3B and 3C into a configuration having the ends of the seal lips 33a and 33b coming close into contact with each other. Accordingly, as shown in FIG. 3, the glass runs 3A, 3B and 3C have been formed into a configuration having the side walls 32a and 32b increasingly spread apart from each other in the direction of an opening 35 of the glass run 3 so as to separate the ends of the seal lips 33b and 33a from each other. The molded corner parts 3E and 3D for connecting the extruded glass runs 3A, 3B and 3C are also formed into a configuration wherein the side walls increasingly spread apart in the direction of their openings, which is substantially identical to that of the extruded glass runs 3A, 3B and 3C (FIG. 3).
The glass run 3 thus formed has been mounted to the channel 20 by pinching the side walls 32a and 32b with fingers or the like and pressing them in the directions of the white arrows in FIG. 3 such that the side walls 32a and 32b turn about angular portions 31a and 31b into approximately parallel relation to each other.
However, when the glass run 3 is mounted to the channel 20, widthwise ends of the bottom wall 31 interfere with opening ends 21 of the channel 20. To overcome this problem, the glass run 3 has been tilted with respect to the channel 20 into a readily insertable posture upon inserting it into the channel 20. With this method as shown in FIG. 4, the molding lip 34a or the above-described projection may enter channel 20 causing a problem. In particular, as shown, where the side walls 32a and 32b have different heights, the above-described problem may frequently occur. Consequently, the work efficiency in attaching the glass run 3 is low.
When the corner part 3D, which curves at an approximate right angle, is mounted to the channel 20 by pressing the side walls 32a and 32b into a generally parallel relation, end portions of the side walls 32a and 32b, which are on the radial inside thereof, are compressed in the curving direction thereof. Consequently, as shown in FIG. 5, the side walls 32a and 32b, molding lips 34a and 34b, and seal lips 33a and 33b respectively, generate a surplus 7 which protrudes outwardly from the center of the corner part 3D.
Thus, to fit the molded corner part 3D to the channel 20, a large pressing force is needed. Consequently, the work efficiency in attaching the glass run is low. The resultant protrusions in the seal lips 33a and 33b decrease the effectiveness of the seal provided against the door glass 6. Also, the resultant protrusions in the side walls 32a and 32b, and molding lips 34a and 34b impair the close fit against the side walls of the channel 20, and cause the generation of gaps between ends of the molding lips 34a and 34b and the side walls of the channel 20, degrading the external appearance around the door frame 2.